I was speaking with a colleague last week about digital identity systems. We got to thinking about all of the hoopla around federated identity systems that began with Microsoft's ill-fated launch of Hailstorm which then, of course, led to the rest of the industry's Liberty Alliance response.
Then he made an interesting comment: arguably the largest federated identity system currently in use on the planet is Visa's Verified by Visa scheme.
Think about it: a three-party (cardholder, merchant, card issuer) identity management solution that already has millions of participating parties conducting more secure commerce transactions.